Seasonal affective disorder

Definition

Seasonal affective disorder (SAD) is a kind of depression that occurs at a certain time of the year, usually in the winter.

Causes, incidence, and risk factors

SAD may begin during the teen years or in adulthood. Like other forms of depression, it occurs more often in women than in men.

People who live in places with long winter nights are at greater risk for SAD. A less common form of the disorder involves depression during the summer months.

Symptoms

Symptoms usually build up slowly in the late autumn and winter months. Symptoms are usually the same as with other forms of depression:

Hopelessness

Increased appetite with weight gain (weight loss is more common with other forms of depression)

Increased sleep (too little sleep is more common with other forms of depression)

Less energy and ability to concentrate

Loss of interest in work or other activities

Sluggish movements

Social withdrawal

Unhappiness and irritability

SAD can sometimes become long-term depression. Bipolar disorder or thoughts of suicide are also possible.

Signs and tests

There is no test for SAD. Your health care provider can make a diagnosis by asking about your history of symptoms.

The health care provider may also perform a physical exam and blood tests to rule out other disorders that are similar to SAD.

Treatment

As with other types of depression, antidepressant medications and talk therapy can be effective.

MANAGING YOUR DEPRESSION AT HOME

To manage your symptoms at home:

Get enough sleep.

Eat a healthy diet.

Take medicines the right way. Learn how to manage side effects.

Learn to watch for early signs that your depression is getting worse. Have a plan if it does get worse.

Try to exercise more often. Look for activities that make you happy.

Practice good sleep habits.

Avoid alcohol and illegal drugs. These can make depression worse over time. They may also affect your judgment about suicide.

When you are struggling with depression, talk about how you're feeling to someone you trust. Try to be around people who are caring and positive. Volunteer or get involved in group activities.

LIGHT THERAPY

Light therapy using a special lamp with a very bright light (10,000 lux) that mimics light from the sun may also be helpful.

Start treatment during the fall or early winter, before the symptoms of SAD begin.

Follow your health care provider's instructions about how to use light therapy. A common practice is to sit a couple of feet away from the light box for about 30 minutes every day. This is usually done in the early morning, to mimic sunrise.

Keep your eyes open, but do not look straight into the light source.

Symptoms of depression should improve within 3 - 4 weeks if light therapy is going to help.